Furnace stoker



L. A. WARD Feb. 7, 1939.

FURNACE STOKER Filed April 16 1037 I5 Sheets-Sheet l INVENTOR; LfO/VAAD A WA fPD.

ATTORNEY.

L, A, WARD 2,146,198

FURNACE STOKER Feb. 7, 1939.

5 Sheets-Sheet 2 Filed April 16, 1937 HHLMMM.

INVENTOR. LEONA/P0 A M490.

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Feb. 7, 1939. L. A. WARD 2,146,198

FURNACE STOKER Filed April 16, 1937 5 Sheets-Sheet I5 INVENTOR. Lao/m 0 A. WARD.

BY ATTORNEY.

Patented Feb. 7, 1939 UNITED. STATES PATENT OFFICE 8 Claims.

This invention relates to a stoker for feeding coal to a furnace and is designed as an improvement over the stoker illustrated and described in applicant's copending application Serial No. 115,714.

The principal object of the invention is to provide a small compact, simple, portable, eflicient stoker unit which can be applied to the present household plants without requiring any change in the present heating system.

Other objects of the invention are to provide positive controllable mechanism for feeding the coal to the burner; to provide means for preventing the coal from packing or clogging the stoker;

to provide means for breaking lumps of coal to the proper size for feeding to the burner; to provide automatic means for shutting off the operating motor should iron or other non-breakable foreign substances become locked in the mecha- 2 nism.

Other advantages reside in the detail construction of the invention, which is designed for simplicity, economy, and efliciency. These will become more apparent from the following de- 25 scription.

In the following detailed description of the invention reference is had to the accompanying drawings which form a part hereof. Like numerals refer to like parts in all views of the 30 drawings and throughout the description.

In the drawings:-

Fig. 1 is a plan view of the improved stoker partially broken away to show the interior construction.

3 Fig. 2 is a detail section through the burner portion of the device.

Fig. 3 is a left side view of the stoker with the casing partially broken away.

Fig. 4 is a detail sectional view through the 40 feed cam housing.

Fig. 5 is a face view of the feeder cam housing. Fig. 6 is a vertical cross section through the stoker portion, taken on the line 5-6, Fig. 1.

Fig. '1 is a detail view through the upper extremity of the feed tube.

The invention comprises a cabinet-like housing Ill supported on suitable legs ii and provided in its lower portion with a supporting frame I2. 5 A coal hopper I3 is formed in the upper portion of the cabinet l0 leading to a laterally extending feed screw chamber l4.

A feed screw I5 is supported in the feed screw chamber l4 upon a feed screw shaft IS. The

55 feed screw chamber [4 opens through a jagged breaker opening II into a feed chamber i3 from which a rotary feed tube 13 leads.

The feed tube i9 is inclined downwardly to a burner base positioned within the ash pit of the furnace. The burner base is formed with a 5 curved passage 2| which directs the coal discharging from the feed tube upwardly into an inverted conical burner 22.

The burner 22 is surrounded by an air chamber 23 and by tuyeres 24 formed through the 10 wall of the burner and communicating with the air chamber. Air is supplied to the air chamber 23 through a conduit 25 from a blower 26 within the cabinet I0.

The blower is driven from a suitable electric 16 motor 21, the shaft of which, shown at 23,-extends through the blower and terminates in a worm 23 in a gear housing surrounding-the feed tube 19. The worm 29 drives a worm gear 3| which is secured on the feed tube l9 and rotates the latter. 20

The gear housing 30 is extended along the feed tube 13 and forms a bearing for the latter. The housing is supported upon suitable brackets 32 from the'supporting frame 12. The feed screw I5 is rotated from the rotating feed tube i3 25 through .the medium of a tie bar 33 which is welded to the interior of the feed tube at one extremity and rotates a hollow shaft 34 at its other extremity.

The hollow shaft carries a cam 35 within a 30 cam housing 36. A lever 31 rests by gravity on the cam 35. One extremity of the lever is carried on a cross shaft 38. .The other extremity of the lever carries a ratchet pawl 33. The ratchet pawl 39 is formed with a counter-weight 40 which 36 constantly holds it in engagement with the teeth of the ratchet wheel 4|. The ratchet wheel 4| is fastened on the extremity of the feed screw shaft l6 and rotates the latter. A check pawl 42 is provided to prevent return rotation of the 40 shaft iii. The downward arc of movement of the lever 3'! can be limited by means of an adjustment screw 43 positioned beneath the lever.

The cross shaft 33 at the other extremity of the lever 31 passes through vertically slotted holes 44 in the sides of the housing 36 and rests in bottom half bearings 45. The shaft is held down in the half-bearings 45 by upper half-bearings 46 which are carried on the extremities of an inverted U-shaped yoke 41. The yoke 41 is constantly pressed downward by means of a spring 48 which is clamped by a clamp nut 49 on a spring stud 50.

Should a piece of iron, rock or other unbreakable substance reach the feed screw and become a ratchet wheel ward compressing the spring 48 to allow ing loop It to lodged in the breaker opening I! it will become impossible ior the ratchet pawl II to turn the ratchet wheel II. The up thrust oi the cam ll will then cause the rearward extremity oi the lever 41 to raise. This will push the yoke the cam to pass beneath the lever without damage.

Means are also provided ior shutting oi! the motor 21 onsuchan occasionbyplacingapress button switch Ii in the'path oi an arm I! which is connected with the yoke 41. -Theswitch Ii isconnectedinthe circuit oi the motor :1. Thus. as the yoke moves upwardly in the direction oi the broken line in Fig.5 it will shut oil the current supply to the motor 2!, stopping thestokeruntil theobstructioncanberemoved.

Naturally as the ieed tube is rotates, the bar 8| will swing in a cylindrical path thus acting as an agitator to prevent clogging oi the coal in the feed chamber ll.

' Clowns oi the coal in the iced tube is preventedbgmeansoianagitator barll whichextends throughout the length oi the tube adjacent the upperwallthereoiandwhichtorminatesatits upper extremity in a weighted lever II.

can thenmanually engage the lever II and The lower extremity of the bar II is journalled on a screw member 55 at the lower extremity oi the ieed This screw 55 extends outwardly irom the lower extremity oi the iced tube and is welded or otherwise secured therein so that it will rotate with the tube and ioroe the coal into the burner base 2|. The lower extremity oi the ieed tube is supported in a bearing member II provided with suitable ball bearings 81.

The coal is prevented from packing in the bottom oi the hopper II by means oi an agitating loop 58 which is universally hinged therein at'its one extremity in an eye bolt 50 and is mounted on a crank so at its other extremity. The crank 80 extends through the side wall oi the hopper and carries a slotted lever ll which extends downwardly opposite the extremity oi the screw shait l6.

Acrankdlsctiismountedon thescrewshait at this point and provided with a crank pin II which passes through and rides in the slot in'the lever 6|. It can be seen that as'the shait ll rotates the crank pin it will oscillate the agitatprevent-packing oi the coal in the hopper.

It might be possible for m to back up through the ieed tube into the ieed chamber II. This gas is then withdrawn through a gas conduit 04 extending tothe intake oi the blower it.

While a specific iorm oi the improvement has been described and illustrated herein, it is desiredtobeunderstoodthatthesamemaybe varied, within thescope oi' the appended claims, without departing irom the spirit oi the invention.

Having thus described the invention, what is claimed and desired secured by Letters Patent is:-- i

1. In a stoker oi the secured to said screw; a cam shait adjacent said screw; a cam on said cam shait; a lever lying across said cam; a ratchet type having a ieed screw;

pawl at one extremity oi said lever engaging said ratchet wheel so that as said cam rotates, it will reciprocate said pawl to rotate said ratchet wheel.

an overload release device comprising: a pivot member supporting the other extremity oi said lever; means ior allowing said pivot member to stoker control-switch operated by the lateral movement oi said pivot member.

3. In a stoker oi the type having a ieed screw; a ratchet wheel secured to said screw; a cam shait adjacent said screw; a cam on said cam shait; a lever lying across said cam; a ratchet pawl at one extremity oi said lever engagingsaid ratchet wheel so that as said cam rotates, it will reciprocate said pawl to rotate said ratchet wheel. an overload release device comprising: a pivot shait extending through the other extremity oi said lever; stationary bearing members supporting said pivot shait; and movable bearing members holding said pivot shait down against said stationary members and a spring acting against said movable bearing members.

3. ins stoker oi the type having a i'eed screw; a ratchet wheel secured to said screw; a cam shait adjacent said screw; shait; a lever lyingacross said cam; a ratchet pawl at one extremity oi said lever n aging said ratchetwheel so that as said cam rotates, it will reciprocate said pawl to rotate said ratchet 7 wheel. an overload release device comprising: a

pivot shait extending through the other extremity of said lever; stationary bearing members supporting said pivot shait; movable members holding said pivot shait down against said stationary members; a yoke extending between said vmovable bearing members; and a spring iorcing said yoke and said movable bearing members downwardly against said pivot shait.

4. In a stoker oi the type having a ieed screw;

a ratchet wheel secured to said screw; acam shait adjacent said screw; a cam on said cam shait; a lever lying across said cam; a ratchet pawl at one extremity oi said lever engaging said ratchet wheel so that as said cam rotates. it will reciprocate said pawl to rotate said ratchet wheel.

acamonsaidcam' bearing an overload release device comprising: a pivot shait extending through the other extremity of said lever; stationary bearing members supporting said pivot shait; movable bearing members holding said pivot shait down against said stationary members; a yoke extending between said movable bearing members; a spring forcing said yoke and said movable bearing members downwardly against said pivot shait; and a control switch actuated by the upward movement oi said yo e.

5. The combination oi a cam; a motor driving said cam; a lever extending across and resting against said cam; a ratchet drive device actuated by the movement of one extremity oi said lever; a cross shait pivotally supporting the other extremity oi said lever; receiving means ior supporting said cross shait; and resilient means holding said against said cam; a ratchet drive device actuated by the movement of one extremity of said lever; a

cross shait pivotally supporting the other extremity oi said lever; receiving means ior supporting said cross shaft; resilient means holding said cross shaft in said receiving means until the resistance of said ratchet drive reaches a pre-deter: mined point; and an electric switch in circuit with said motor positioned to be actuated in consequence of the movement of said cross shaft from said receiving means.

7. The combination of a cam; a motor driving said cam; a lever extending across and resting against said cam; a ratchet drive device actuated by the movement of one extremity of said lever: a cross shaft pivotally supporting the other extremity of said lever; a fixed half bearing for each extremity of said cross shaft, said bearings being positioned on the cam side of said lever; a movable half bearing holding the cross shaft in each fixed half bearing; a yoke member extending between said movable half bearings; a spring forcing said yoke and said movable bearings against said shaft to hold the latter in said fixed bearings until the load on said ratchet drive' reaches a predetermined point.

8. The combination of a cam; a motor driving said cam; a lever extending across and resting against said cam; a ratchet drive device actuated by the movement of one extremity of said lever; a cross shaft pivotally supporting the other extremity of said lever; a fixed half bearing for each extremity of said cross shaft, said bearings being positioned on the cam side of said lever; a movable half bearing holding the cross shaft in each fixed half bearing; a yoke member extending between said movable half bearings; a spring forcing said yoke and said movable bearings against said shaft to hold the latter in said fixed bearings until the load on said ratchet drive reaches a predetermined point; and an electric switch for controlling the operation of said motor in consequence of the movement of said yoke against said spring.

LEONARD A. WARD. 

